The “one purpose” of the weapons used in Aurora (the movie theater in Colorado) and Sandy Hook, according to the president, is “to pump out as many bullets as possible, as quickly as possible.” This description does not distinguish those weapons from the millions of other semi-automatics (and high-capacity magazines) currently in the hands of law-abiding Americans.
The Washington Post reports that when the 1994 ban went into effect, “there were roughly 1.5 million assault weapons and more than 24 million high-capacity magazines in private hands” (and that was just “assault weapons” according to the limited definition of the 1994 ban — not all semi-automatics). There are many more now, and none of those weapons or magazines already produced were affected by the ban. Nor are the bullets those “assault weapons” fire — the .223 Remington — different in any way from those widely in use in all those other semi-automatic rifles.
The president’s reference to “bullets often designed to inflict maximum damage” presumably refers to hollow-points, bullets designed to expand on impact. But is the president seriously proposing to ban all hollow-point ammunition? If so, it is not accurate to say that his attempt to restrict “military style” weapons and limit the capacity of magazines would have no effect whatsoever on the likelihood or lethality of mass shootings. Indeed, banning hollow-points would almost certainly make future shootings — at least future shootings conducted with federally approved ammunition — much more lethal.
Solid bullets penetrate walls, doors, bodies, etc.; hollow points do not, or do so rarely.
In fact, limiting magazine size can also be predicted to cause more rather than fewer fatalities. As I argued here:
Indeed, a perfectly predictable but unintended consequence of banning high-capacity magazines would be to decrease the appeal of 9mm handguns and increase the popularity of more the powerful and lethal .40 and .45 caliber and .357 Magnum, since the main appeal of the 9mm has always been its higher-capacity magazines.
As with many “reforms,” the president’s proposals are sure to be ineffectual if implemented, and in some cases are far worse than doing nothing.